Unloading failure of rocks,especially highly stressed rocks,is one of the key issues in construction of underground structures.Based on this,analytical models for rocks under quasi-static and intensive unloading condi...Unloading failure of rocks,especially highly stressed rocks,is one of the key issues in construction of underground structures.Based on this,analytical models for rocks under quasi-static and intensive unloading conditions are established to study the failure behavior of highly stressed rocks.In case of rock failure under quasi-static unloading,the rock mass ahead of working face is regarded as an elasto-brittle material,and the stress-displacement curves are used to characterize the tensile fracture of peak-stress area.It is observed that,when intensive unloading happens,there is an elastic unloading wave（perturbation wave） propagating in the rock mass.If the initial stress exceeds the critical stress,there will be a fracture wave,following the elastic unloading wave.To study the propagation feature of fracture wave,the conservation laws of mass,momentum and energy are employed.Results show that the post-peak deformation,strength and energy dissipation are essential to the failure process of highly stressed rocks.展开更多
Slopes consisting of interbedded strata of soft and hard rock mass, such as purplish red mudstone and grey brown arkosic sandstone of Jurassic age, are very common in Sichuan basin of China. The mudstone is soft whil...Slopes consisting of interbedded strata of soft and hard rock mass, such as purplish red mudstone and grey brown arkosic sandstone of Jurassic age, are very common in Sichuan basin of China. The mudstone is soft while the sandstone is hard and contains many opening or closing joints with a high dip angle. Some are nearly parallel and the others are nearly decussated with the trend of the slopes. Many natural slopes are in deformation or sliding because of those reasons. The stability of cutting slopes and supporting method to be taken for their stability in civil engineering are important. In this paper, the stability and deformation of the slopes are studied. The methods of analysis and support design principle are analyzed also. Finally, the method put forward is applied to study Fengdian high cutting slope in Sichuan section of the express way from Chengdu to Shanghai. The results indicate that the method is effective.展开更多
基金sponsored by the National Science Fund for Distinguished Young Scholars(50825403)the National Key Basic Research Program of China(2010CB732003,2013CB036005)the Science Fund for Creative Research Group of the National Natural Science Foundation of China(51021001)
文摘Unloading failure of rocks,especially highly stressed rocks,is one of the key issues in construction of underground structures.Based on this,analytical models for rocks under quasi-static and intensive unloading conditions are established to study the failure behavior of highly stressed rocks.In case of rock failure under quasi-static unloading,the rock mass ahead of working face is regarded as an elasto-brittle material,and the stress-displacement curves are used to characterize the tensile fracture of peak-stress area.It is observed that,when intensive unloading happens,there is an elastic unloading wave（perturbation wave） propagating in the rock mass.If the initial stress exceeds the critical stress,there will be a fracture wave,following the elastic unloading wave.To study the propagation feature of fracture wave,the conservation laws of mass,momentum and energy are employed.Results show that the post-peak deformation,strength and energy dissipation are essential to the failure process of highly stressed rocks.
文摘Slopes consisting of interbedded strata of soft and hard rock mass, such as purplish red mudstone and grey brown arkosic sandstone of Jurassic age, are very common in Sichuan basin of China. The mudstone is soft while the sandstone is hard and contains many opening or closing joints with a high dip angle. Some are nearly parallel and the others are nearly decussated with the trend of the slopes. Many natural slopes are in deformation or sliding because of those reasons. The stability of cutting slopes and supporting method to be taken for their stability in civil engineering are important. In this paper, the stability and deformation of the slopes are studied. The methods of analysis and support design principle are analyzed also. Finally, the method put forward is applied to study Fengdian high cutting slope in Sichuan section of the express way from Chengdu to Shanghai. The results indicate that the method is effective.
